Sustainable aviation fuels and imminent technologies - CO2 emissions evolution towards 2050

Nowadays, concerns about rising emissions and climate change have raised the issue of decarbonization. Several approaches have been promoted in the aeronautical sector to reduce CO2 emissions. The present work provides quantitative data to support decision-making for the first pillar of International Air Transport Association (IATA) strategy to mitigate aviation climate impact. This strategy comprises improving aircraft technology and deploying sustainable low-carbon fuels. The most promising technologies for an imminent application are new engine architecture and natural laminar flow. On the other hand, efforts have been put to produce Sustainable Aviation Fuel (SAF) reaching the point where some methods for the production of alternative jet fuel are already approved by ASTM. Therefore, the present work quantifies the future reduction of CO2 emissions by 2050 in the aeronautical sector with these strategies. For this purpose, two methodologies are used, a numerical model to calculate fuel consumption and CO2 emissions from the global air transport fleet. For the SAF analysis, it is developed an approach that considers, besides the SAF production, the feedstocks, and the production pathway. Two cases and three scenarios represent the technological improvements and quantify the effects of new aircraft concepts and technologies on future CO2 emissions. For the SAF analysis, four scenarios and two conditions assess the different production capacities and feedstocks. The combined effect of technologies with SAF is considered verifying if the goals proposed by IATA, carbon-neutral growth from 2020, and a reduction of 50% in net emissions by 2050 compared to 2005 levels are achieved. The assessment results reveal that the goals cannot be met only with the combined action of imminent aircraft technologies and the use of alternative fuels. Carbon-neutral growth is only reached when it is considered the combined effect of technologies with the scenario where the amount of SAF introduced is higher (an increase of 15% annually between 2030 and 2050). However, this carbon-neutral growth is only possible to start in 2040. Imminent aircraft technologies can reduce up to 15% in CO2 emissions when compared to the Business as Usual scenario. The different feedstocks used in each process to produce SAF do not have a considerable impact on reducing CO2 emissions, the maximum difference registered between each condition was 1.47%.Fundação para a Ciência e a Tecnologia